1. Field of Invention
The invention relates to a suspension device for lowerable luggage stowage compartments comprising at least one spring element for assisting the movement of the compartment into its closed position contrary to gravity, and at least one damping element for damping the movement of the compartment into its opened position, and comprising a means for detecting the weight of the compartment and at least one additional spring element capable of being activated or switched over in dependence on the detected weight of the compartment, a retention device being provided for fixing the at least one additional spring element.
Furthermore, the invention relates to a lowerable luggage stowage compartment comprising such a suspension device, wherein at least one spring element is arranged between the compartment and a stationary structural element laterally of the compartment so as to assist in the movement of the compartment into its closed position contrary to gravity, and at least one damping element is arranged for damping the movement of the compartment into its opened position, a means for detecting the weight of the compartment being connected to the compartment part.
The present invention mainly relates to a luggage stowage compartment as is used in passenger aircraft. However, it is also applicable to luggage stowage compartments as, e.g., used in rail-borne vehicles or in other transport devices adapted for passenger transportation.
2. Description of the Prior Art
Luggage stowage compartments in passenger aircraft usually consist of cases mounted above the passengers' heads and having an opening that is closable e.g. by means of a pivotable flap. To put an item of luggage into the compartment or to remove it therefrom, the passenger must open the flap and lift his/her item of luggage through the opening into the compartment or remove it therefrom. This requires a considerable effort, particularly if the items of luggage are heavy, and this may be an impediment for short or weak persons.
To improve the situation, particularly in very large passenger aircraft which also have a greater cabin height, luggage stowage compartments have been developed which can be pivoted downwards or lowered for the purpose of loading and unloading the same. Such pivoting or lowering mechanisms usually comprise at least one damping element which dampens the downward movement of the compartment so that the compartment will not drop down abruptly during opening of the latter and cannot cause injuries. In addition, such a mechanism comprises at least one spring element which assists the movement of the compartment contrary to gravity into its closed position and thus makes it easier for the passenger to close the loaded compartment. These damping and spring elements are adjusted such that they will provide a sufficient damping for a luggage stowage compartment bearing an average load, and will sufficiently assist the movement into its closed position. If the load of the compartment deviates from this average value to which the damping and spring elements have been adjusted, the mechanism will not function as desired. Thus, an empty compartment would be only very difficult to be moved into its open position, contrary to the action of the damping element, allowing an opening of the compartment only by exerting a relatively high tensile force. On the other hand, it would be difficult and possible only by using physical activity to move an overloaded compartment into its closed position contrary to gravity. The problem is aggravated by the fact that for future aircraft designed for ever increasing numbers of passengers, the luggage stowage containes have to be built of increasingly larger sizes and have to withstand ever increasing loads. Such luggage stowage compartments may, e.g., be designed for loads of from 0 to 60 kg. Accordingly, it is nearly impossible to design a pivoting or lowering mechanism for such a luggage stowage compartment which will be the best for all loads.
DE 41 30 644 A1 shows an overhead luggage stowage device whose handling will require little actuation effort and which is largely independent of the load added and the position of the movable compartment. For this purpose, the gas spring provided to assist the closing procedure is pivotably arranged so that the hinge point on the upper lever and, thus, the torque acting on the upper lever thereby assisting the closing procedure of the compartment are changeable. The weight of the movable compartment of the overhead luggage stowage device is detected by a weighing pin which acts on a weighing lever connected to the spring element. Depending on the weight of the compartment's load, the gas spring will be pivoted more or less, and thereby the weight force of the compartment will be compensated. To prevent the gas spring from being pivotable into its original position during the closing procedure of the compartment, a blocking means is provided which is actuated via a Bowden cable as soon as a pressure is exerted on the arresting plate at the lower side of the pivotable compartment so as to initiate the switching procedure. In addition, when a certain height of the lowerable compartment has been reached, the blocking device is automatically actuated so that it will also be active independently of the state of the Bowden cable.
DE 43 35 151 A1 also shows an overhead luggage stowage device comprising a lowerable compartment wherein a further spring element can be activated in dependence on the loading of the compartment so as to assist in the closing procedure. If the compartment is not loaded or only slightly loaded, a supporting lever connected to the additional spring element is blocked so that the additional spring element will not exert an additional force on the compartment. If the load of the compartment exceeds a certain limiting value which is detected by the load-caused deflection of the movable compartment, the blocking of the supporting lever can be released by an active pressure from the bottom on a triggering plate on the movable compartment part, and the additional spring element will act to assist in the closing procedure. Between the triggering plate and the supporting lever, a Bowden cable is arranged to transmit the pressure onto the triggering plate on the blocking hook. Therefore, an active participation of the passenger is of necessity required for an activation of the supporting spring, and this renders an operation thereof difficult. The connection between the triggering plate and the blocking hook of the supporting gas spring required of necessity also makes mounting and maintenance more complex and makes it more susceptible to failure.